Sampling over 12 months has found microplastics at all 10 sites monitored.
The council is urging the Government to provide millions in funding to remove the invasive seaweed.
All over Aotearoa, people are watching the waters for a glimpse of marine mammal activity to contribute to the fifth annual survey.
"The scale of it is so wrong, the lack of respect for nature is so wrong."
It's thought the local landscape could be to blame.
The survey was carried out just days before the demonstrations.
Juvenile fur seals and sea lions are often found in unusual locations between June and September, when they begin exploring further afield from their usual habitats.
Low confidence in the government's climate plans may hit the coalition in the pocket.
"I feel a bit bitter about it because we did so much work."
